1. Field of the Invention
The invention is directed to an inflatable appendage located at the rear of a vehicle and especially of a truck or trailer having a flat rear surface. The appendage modifies the aerodynamic shape of a truck so that the low pressure created at the rear of a moving truck which produces a drag on the latter, is replaced by a zone of high pressure. The present appendage which acts as a drag reducer operates in an autonomous manner without assistance from the vehicle operator.
2. Prior Art
U.S. Pat. No. 4,741,569 discloses an inflatable drag reducer made of non-porous air bags inflated with a blower motor.
In U.S. Pat. No. 4,236,745, metal tubing, are used to support adjacent sleeve members, thereby necessitating an elaborate and heavy structure.
The appendage contemplated by Paul D. Kerian in U.S. Pat. No. 4,601,508 requires a duct beneath the truck to supply air to the plenum chamber (col. 4, line 23) at the center of the rear of the truck.
E. L. Keedy discloses in U.S. Pat. No. 4,142,755 a drag reducer made of an assembly of rods or rigid panels hingedly mounted on the rear surface of the truck. These elements maintain the shape of the drag reducer with little use of an air scoop which is not described and which may have a preventive use only.